Barcode Scanner Connections

The Barcode Scanner Connection is Key

Since the barcode scanner will connect to the PC, you must make sure you select the right connection type. Most corded barcode scanners on the market today are "multi-interface". That means that the scanner itself can communicate a variety of ways to the computer it's attached to. All you have to do is make sure you have the right cable and you've programmed the scanner so it knows how to talk. There are four connection types for corded barcode scanners:

USB - The barcode scanner connects to the PC using a USB port. When you plug in the scanner, the operating system will recognize it as a keyboard or a HID (human input device). USB connections are the most common in the industry today.

Keyboard Wedge - The barcode scanner connects to the computer on a "Y" cable with the keyboard that comes with the scanner. The bottom of the Y connects to the AT or PS2 keyboard port. Before USB, this was the most popular connection for corded barcode scanners.

RS232 Serial - With this connection, the barcode scanner is communicating with the PC over a serial port. The cable to the scanner connects with a 9 or 25 pin female connector to the COM1 or COM2 ports in the back of the computer. This interface is commonly used to allow barcode scanners to connect directly to industrial controllers or other automated equipment. If you want your desktop PC to communicate using a serial interface, you'll have to make sure that your application software (where you want the scanner data to go) is set up for serial connections. You have to know the Baud Rate, Stop Bits, and Parity for the communication expected by the software, and set those same values in the firmware of the barcode scanner. Normally, these connection types require an external power supply as the serial port can't supply enough to power the barcode scanner.

Interface Controller - Sometime, specialized computing equipment will be set up with proprietary interface connections for the barcode scanner. Examples of these are ISBT-128, Ruby Verifone, Nixdorf Beetle, and IBM Port 9B. By definition, these scanners come with the specialized cable required, and are programmed appropriately for communications with what they're plugged into.

Included in this type of connection is the barcode scanner that is connected to a "decoder". That means that the scanner is sending the raw barcode data to another piece of equipment called a decoder that converts the signal to ASCII text and sends it to the computer. You can find out more in the Corded Barcode Scanner Types section